1. Field of the Invention
This invention relates to a spiked-bumper of a portable chain saw generally used for felling trees and producing lumber.
2. Description of the Prior Art
Generally, a chain saw usually has a spiked-bumper mounted to a forward end portion of a main body of the chain saw in a position close to a guide bar for guiding a saw chain in its movement around an outer periphery of the guide bar. The spiked-bumper is caused to press against a tree or a timber positively before a sawing operation is performed to prevent an accident from occurring inadvertently as the main body of the chain saw is pulled suddenly toward the tree or timber or the saw chain slips during operations.
Some disadvantages are associated with the spiked-bumper of the prior art. One of them is that the optimum range of application of the spiked-bumper is narrow with regard to the shape and diameter of the trees and timbers constituting the objects of the operation, so that a multiplicity of spiked-bumpers should be provided to be fitted to different types of sizes of chain saw.